The invention concerns a steering column assembly for arranging in the area of a steering column in a motor vehicle, comprising a locating device, a centrally arranged support board and at least one steering column switch, whereby the locating device comprises a receptacle for the support board and at least one receptacle for the switch; the switch is disconnectably connected to the locating device; the switch comprises a control, and the control, depending on its manually selectable position, by way of a control means acts upon at least one switch element causing signal indication.
Switches arranged on a steering column assembly are used to operate and control various functions of the vehicle. Such functions can, for example, be switching the vehicle lights on and off, initiating the turn signals or the windscreen wiper device, operating an automatic cruise control etc. The intention is to allow operation and control of as many functions of a vehicle as possible in close proximity to the steering wheel. Such an arrangement ensures that the driver can reach the controls without having to take whichever hand is necessary for operating the control away from the steering wheel region.
Apart from increasing operational safety, another requirement is simplification in manufacture and assembly of the elements necessary for operating and controlling the various functions. This applies in particular to such components of the switches concerned which are exposed to premature destruction or increased wear.
A switch of the type mentioned in the introduction is known from DE 44 32 343 A1. With the known switch, a switch lever which is swivellably retained in a housing, is used as a control. The floor of the housing is a support board on which three commercially available microswitches with press function are arranged. In this, the microswitches are arranged in an arc, spaced apart at 90.degree. angles; each switch is connected by a spring-elastic switch clip. By way of the switch clips, the switch travel of the switch lever which is much larger than the switch travel of the microswitches, is transferred only in a limited way to the respective microswitch.
The above-mentioned embodiment of the known switch enables economic production of such a switch, using commercially available components. However, the known switch has the disadvantage that it has to be exchanged as a unit in the case of a defect of even one single microswitch. In addition, the microswitches housed in the switch housing have proven to be prone to malfunction. Finally, the known switch is difficult to install as a result of the loom of cables connected to it.
A switch similar to the switch just described is known from DE 43 32 748 A1. With this switch, optical switches instead of microswitches are provided on a support board. In comparison to the switch described above, this switch is additionally also configured in such a way that the electrical connection is established at the same time as the switch is connected to a locating device.
From DE 44 28 883 C1 a steering column assembly is known in which the problem of difficult installation as a result of the looms of cables no longer exists. In the known device, the electrical control unit is configured in the form of a printed circuit board on which sensor means, for example a steering angle sensor, are arranged. In addition, the printed circuit board comprises press contacts as well as plug-in contact elements with which the printed circuit board is coupled with the respective supply lines during installation. In addition, switches configured as steering column levers are provided which comprise lever-like control members and which point essentially in a radial direction in relation to the steering shaft. To establish an electrical connection to the central printed circuit board, each steering column lever is equipped with a further printed circuit board which is accommodated in a switch housing provided for this. At their end opposite the control means, these switch housings comprise an aperture for establishing the necessary connections with the remaining functional components of the modular unit. In this way the press contacts of the printed circuit board can be connected to establish functional contact with the contact surfaces provided on the two additional printed circuit boards.
This known embodiment of a steering column assembly first of all provides for significantly easier installation. Nonetheless the problem remains that with the known system the steering column levers have to be exchanged as a unit if a mechanical or electrical defect occurs. In addition, practical tests have shown that due to dirt or corrosion, the electrical switch elements of the steering column levers are prematurely unserviceable. In addition, it is problematic that the electrical contacts formed between the further printed circuit boards and the central printed circuit board, are affected by multiple activation and that production of further printed circuit boards on the one hand and the central printed circuit board on the other hand is expensive.
A further design of a steering column assembly for motor vehicles, in particular of a steering column switch for this steering column, is known from EP 0 687 593 A2. In this, the steering column switch is in contact with the signal transmitting device by positive connection of the housing of the steering column switch with a fixed housing part of the signal transmitting device.
Furthermore, from practical application, ignition locks for motor vehicles are known which can be inserted into a housing located below the steering wheel, in the region of the steering column. Such purely mechanical locks comprise a receptacle for the key as well as an eccentric pin as a release element.
Starting from the state of the art as discussed above, it is the object of the invention to create a steering column assembly, for arranging in the area of a steering column in a motor, vehicle which enables simple installation of the switches arranged on the steering column assembly and in which the switches can be replaced economically if a defect occurs.